The 2017 US Open Cup will feature 99 teams, per US Soccer's March 1 announcement of the overall field and format of this year's competition.
The draw for the First Round of USOC will feature 56 teams: the PDL and NPSL entrants as well as all the "local qualifiers" who had been thought to be due another qualifying round to reduce their number. But US Soccer has decided all remaining local qualifiers get to advance to the first round, which means FC Motown (the team coached by former RBNY Homegrown player Sacir Hot) will be in the draw on April 12.
After first-round pairings have been announced in April, the competition will commence on May 10. On May 17, the Second Round will kick off, with teams from NASL and USL joining the 28 teams advancing from the opening round.
The Third Round will be player on May 31, and will see the 26 teams advancing from the previous set of games reduce themselves to a group of 13.
On June 14, 19 teams from MLS join the 13 survivors from the preceding matches for the Fourth Round. And that 32-team group will supply the teams that play through to the Round of 16 on June 28, the Quarterfinals on July 11, Semifinals on August 9, and Final on September 20.
The New York Red Bulls' MLS squad will enter the competition for the Fourth Round. Reserve teams are prohibited from entering the tournament, so there is no place for NYRB II. The RBNY U-23 team plays in PDL, but did not have a good enough season in 2016 to make its league's list of entrants to the 2017 USOC.
For the full list of confirmed entrants, see US Soccer's official announcement.